The engine immobiliser system is designed to prevent the vehicle from being stolen. This system uses a transponder key ecu that stores the key codes of authorized ignition keys. If an attempt is made to start the engine using an unauthorized key, the ecu sends a signal to the ecm to prohibit fuel delivery and ignition, effectively disabling the engine.

The transponder key coil receives this signal, the transponder key amplifier amplifies it, and then the signal is transmitted to the ecu. The ecu matches the key's id code with the vehicle's id code, which was previously registered in the ecu and then communicates the results to the ecm using sfi communication.
Engine immobiliser system
How to proceed with troubleshootingCoolant
Replacement
Remove no. 1 Engine under cover
Drain engine coolant
Loosen the radiator drain cock plug.
Hint:
Collect the coolant in a container and dispose of it
according to the regulations in your area.
Remove the radiator reservoir cap.
Caution:
Do not remove the radiator ...
Fuel injector
Components
Removal
Discharge fuel system pressure
Caution:
Discharge fuel system pressure
procedures must be performed before
disconnecting any part of the fuel system.
After performing the discharge fuel system
pressure procedures, pressure will remain in
the fuel line ...
Fuel pressure pulsation damper
Components
Removal
Discharge fuel system pressure (see page
fu-9)
Disconnect cable from negative battery
terminal
Remove no. 1 Engine cover (see page es-410)
Remove air cleaner cap sub-assembly (see
page es-411)
Disconnect fuel main tube (see page fu-10)
Remove fuel pres ...